Herbicidal thiocarbimidates, phosphorothiocarbimidates, and phosphorothioimides



United States Patent HEREICHDAL THIOCARBWATES, PHOSPHOR0- 'il ililCARBIh/HDATES, AND Pi-10SPHOROTH10- MHDES Glenn R. Price, South Chicago Heights, and Edward N. Walsh, Chicago Heights, 111., and Chester L. Bewald, San Jose, and Stassen Y. C. Soong, Mountain View, Caiifi, assignors to Stauifer Chemical Company, New York, N.Y., a corporation of Delaware No Drawing. Filed Aug. 16, 1962, Ser. No. 217,281

- 15 Claims. (Ci. 71-23) The present invention is directed to a novel group of phosphorothioimides of the general formula:

R10 0 NR 11 PSS-C wherein R is selected from the group consisting of substituted and unsubstituted lower alkyl radicals, phenyl, carbalkoxyalkyl, and phosphoro ester radicals of the formula:

. wherein R and R are lower alkyl radicals; R is selected from the group consisting of substituted and unsubstituted lower alkyl radicals and substituted and unsubstituted phenyl radicals; and R is selected from the group consisting of substituted and unsubstituted lower alkyl radicals and substituted and unsubstituted phenyl radicals.

Among the suitable lower alkyl radicals for R R R, R and R, as Well as the unsubstituted lower alkyl electives for R R and R are methyl, ethyl, propy-l, butyl, octyl, and. decyl. radicals for R, R and R are the chloroand bromosubstituted radicals such as trichloromethyl, Z-brornoethyl, monochloromethyl, and the like. The substituted phenyl radicals for R R R and R include the haloand alkoXy-substituted groups such as p-chlorophenyl, o-bromophenyl, o-rnethoxyphenyl, p-rnethoxyphenyl, and the like.

Preparation of the novel phosphorothioimides of the invention involves reacting an O,O-dialkylphosphoro'sulfenyl chloride with a thioamide, preferbaly in the presence of a hydrogen halide acceptor. The-reaction maybe carried out attemperatures between about '-100 C. and +100 C., although about room temperature is to be preferred. Various inert solvents may be used (but not acetone) and the mildly exothermic reactions may be easily controlled. Inanany instances, it-wlll be desirable to maintain the reaction temeprature below about 5 0 or C. to prevent decomposition of the products.

After filtration and purification, the products are viscous j oils, solids or semi-solids, usually the lattertwo.

Suitable substituted lower alkylice The following specific examples illustrate the preparation of the novel compounds of the invention:

EXAMPLE 1 To a solution of 18.1 grams (0.10 mole) of N-(pmethoxyphenyl) thioacetamide, 150 cc. of ethyl ether, and 15 ml. of triethylamine (0.12 mole) were slowly added 20.4 grams (0.10 mole) of 0,0-diethylphosphorosulfenyl chloride. The addition was accomplished over a 40 minute period while the solution temperature was held between 10 and 20 C. After the addition was completed, the solution was stirred for one additional hour at room temperature, filtered, and concentrated 'to 50 C. at 1.0 mm. of Hg. The filtrate was recovered and determined to be S (0,0 diethylphosphorothio) N (p-rnethoxyphenyl)thioacetimide. The yield was 35.0 grams and the analysis was 8.4% P, 16.5% S, and 1.16% Cl compared to 8.9% P, 18.3% S, and 0.0% CI, theoretical.

EXAMPLE 2 To a solution consisting of 15.1 grams (0.10 mole) of N-(phenyl) thioacetamide, ml. of ethyl ether, 15 ml. (0.12 mole) of triethylamine were added 20.4 grams (0.10 mole) of 0,0-diethylphosphorosultenyl chloride. The addition was accomplished over a 20 minute period while the solution was cooled to a temperature between 10 and 20 C. After the addition was complete, the reaction mixture was stirred for one hour, filtered and stripped to 50 C. at 1.0 mm. of Hg. The product yield was 30.7

7 grams (97%) of S (0,0 diethylphosphorothio) N (phenyl) thioacetimide, a viscous oil analysing as 9.2% P, 17.6% S, and 0.6% Cl, compared to a theoretically calculated value of 9.7% P, 19.9% S, and 0.0% C1.

The following specific compounds may be prepared in accordance with the procedures shown in Examples 1 and 2, in the yields indicated. Sample analyses are included in the examples.

EXAMPLE 3 S (0,0-dimethylphosphorothio)-N-(phenyl)benzthioimide; yield=82.5% of theory; analysis: found=9.2% P, 17.1% S, and 0.8% Cl; theory=8.4% P, 17.3% S, and 0.0% Cl.

EXAMPLE 4 S ((LO-dimethylphosphorethio)-N-(p-chlorophenyl)- .thiobenzimide; yield=83 of theory; analysis: found: 7.7% P, 20.3% S, and 7.9% Cl; theory=8.0% P. 16.5% S, and 9.2% Cl.

. EXAMPLE 5 a mour 0 s-s c =Nona5 S (0,0 diethylphosphorothio) N (phenyl) omethoXyphenyLth-ioimide; yield= 100% of theory; analysis: found=7.6% P, 14.9% S, and s 0.7% Cl; theory=7.6% P, 15.6% S, and 0.0% Cl;

E AMPLE 6 S (0,0 diethylphosphorothio) N (phenyl) mbromobenZene-thioimide; yield=98.5% of theory; anal- ;ysis: found=6.6% P, 11.9% S, and 18.8% Br; theo1y=6.75% P, 13.9% S, and 17.4% B11 I butoxyphenybhexanimide.

EXAMPLE 7 EXAMPLE 8 S (0,0 dioctylphosphorothio) N (phenyl) omethoxybenzenethioimide; yield=92% of theory.

EXAMPLE 9 S (0,0 dimethylphosphorothio) N (phenyl)- m-bromophenylthioimide; yield=90% of theory; analysis: found=7.2%.P, 13.0% S, and 18.9% Br; theory=7.2% P, 14.8% S, and 18.5% Br.

EXAMPLE 10 S (0,0 dioctylphosphorothio) N (phenyl) mbromophenylthioimide; yield=89.5% of theory; analysis: found=4.9% P, 9.9% S, and 14.4% Br; theory=4.95% P, 10.2% S, and 12.7% Br.

EXAMPLE 1 1 S (0,0 ethyloctylphosphorothio) N (m bromop-chlorophenyl thioacetimide.

S (0,0 diethylphosphorothio) N (phenyl) thiononimide.

EXAMPLE 13 S (0,0 diethylphosphorothio) N (2 chloro 4- l phosphorothiocarbimidates is illustrated in the aforesaid copending application.

compounds are among the thiocarbimidates and phos-' The following specific example Example Compound 14 S (trichloromcthylthio) O (methyl) N (phcnyDthiocarbiinidate.

15 S (carbethoxymothyltllio) O (methyl) N (phenyl) thiocarbimidate.

S-(butylthio)-O-(isopropy1)-N-(phenyl)thiocarbimidatc.

S-gpnenylthio)-O-(isopropyl)-N-(isopropyl)thiocarbimiate.

S(phenylthio)-O-(ethy1)-N-(pl1enyl)thiocarbimidate.

l9 S-(ethylthi0)-O-(is0pr0pyl)-N-(isopropyl)thioearbimidate.

S-[O-(ethyD-O-(octyD-phosphorothio]-O-(isopropyD-N- (phenyl)thiocarbimidate.

21 S-(0,0-diethylpl10sphor0thlo)-O-(isopr0pyl)-N-(pl1cnyl) thiocarhimidate.

22 S-(O, O-dimethylphosphorothio)-O-(isopropyl)-N-(phcnyl) thiocarbimidate.

23 S-(0,0-dipropylpliosphorothio)-O-(isopropyl)-N-(phcnyl) thiocarbimidate.

24 S(0,0-diethylphosphorothio)-O-(etl1yl)-N-(p-olilor0- phenyl)thioearbirnidate.

25 S-(0,0-dicthylphosphorodithio)-O-(othyl)-N-(phenyl) thioformimidate.

20 S-(0,0-diethylpl1osphorcdithio)-O-(ethyl)-N-(phenyl) thiocarbimidate.

27 S-(0,0-dimethylph0sphoroditl1io)-O-(ethyD-N-(phcnyl) thiocarbimidate.

28 S-(0,0-dimethylphosphorothio)-O-(ethyl)-N-(phenyl) thiofonnimidate.

29 S-(0,0-di0ctylpliosphorotl1io)-O-(methy1)-N(phenyl) thiocarbimidate.

30 S-(0,0-diethylphosphorothio)-O-(methyl)'N-(phenyl) thiocarbimidate.

31 S-(0,0-di1netllylphospllorothio)-O-(methyl)-N-(phenyl) thiocarbimidate.

32 S-(carbethoxymethylthio)-O-(ethyD-N-(phcnyl)thiocarbimidate.

The compounds of the present invention were tested for herbicidal activity on some economically important plant species. Unusually high herbicidal activity against wild oats has been observed with most of the compounds of the foregoing examples, especially where the compound is added as a pie-emergent spray to the soil. The following table illustrates typical pre-emergence herbicidal activity of the thiocarbimidates, phosphorothiocarbimidates, and phosphorothioimides on wild oats. The data obtained from plant physiological tests are reported hereinafter as for slight injury, for moderate injury, and for severe injury to plant life. To more specifically define the type of injury observed, the superscripts TD. (tip dead), B. (burn), De. (desiccation), M. (leaf malformation), Ge. (germination), and Ca. (chlorosis), are shown when applicable, where severe plant injury or death occurred.

Table I PRE-EMERGENCE HERBICIDAL ACTIVITY OF THIOCA R BIMIDATES, PHOSPHOROTHIOCARBIMIDATES AND PHOSPHOROTHIOIMIDES ON WILD OATS Hcrbicidal Activity- Wild Oats Compound (Example No.)

In addition to the foregoing activity with wild oats, the

, compounds have been tested for both pro-emergence and post-emergence herbicidal activity on a broad group of common weedpests. The results of such tests are re- Table II R is selected from the class consisting of lower alkyl, phenyl and substituted phenyl, the substituents for the phenyl radicals being selected from the group consisting of haloand alkoxy-.

2. S (0,0 diethylphosphorothio) N (p-methoxyphenyl)thioacetimide.

3. S (0,0-dimethylphosphorothio) N (phenyl)- benzthioimide. r l

. 4. S (0,0 dimethylphosphorothio) N (p chlorophenyl)thiobenzimide.

HERBICIDAL ACTIVITY OF THIOCARBIMIDATES,PHOSPHOROTHIOCARBIMIDATES, AND PHOSlHOROTHIOIMIDES ON SELECTED WEED SPECIES Compound (Example No.)

Pre-emergenee-- Post-emergence- Pro-emergence P ostemergenc Pre-emergenee 8- P est-emergence 9- P re-emergenee 17 P ostemergenee- 18 Pre-ernergenee 18 Postemergenceufln- 20 P re-gmergen ce Pie-emergence herbicidal tests were conducted follow-' ing planting, but prior to emergence of the plants usually the day following planting. The active compounds were applied at a cconcentration of twenty pounds of active material, diluted in water to a volume of eighty gallons, for each planted acre treated. The aqueous herbicidal solution or dispersion was simply sprayed on the preplanted soil from a hand sprayer. After fourteen days, plants were inspected and compared with an untreated control group planted on the same day. Post-emergence herbicidal tests were initiated approximately two weeks following emergence of the test plants. The method of application involved spraying on the plant foliage a 0.2% aqueous solution or dispersion of the active compound to the point of run-off. The concentration of active material when spraying this solution was approximately twentyfive pounds per planted acre. activity was made after fourteen to nineteen days. Although the above tests were accomplished with aqueous dispersions orrsolutions, the toxic compounds may also We claim: 1. A compound of the formula R10 0 NR \ll V PS-S-C\ wherein R and R3 are lower alkyl, R is selected from f 'the class consisting of phenyl and substituted phenyl, and

Evaluation of herbicidal 5. S (0,0 diethylphosphorothio) N (phenyl) omethoxyphenylthioimide.

6. A method of controlling plant life which comprises contacting said plant life with an herbicidal amount of at least one compound of the formula i -SSC R20 ru wherein R and R are lower alkyl, R is selected from the class consisting of phenyl and substituted phenyl, and R is selected from the class consisting of lower alkyl, phenyl and substituted phenyl, the substituents for the phenyl radicals being selected from the group consisting of haloand alkoxy-.

7. A method of controllingplant life which comprises contacting said plant life with an herbicidal amount of S (0,0 diethylphosphorothio) N (p methoxyphenyl) thioacetimide.

8. A method of controlling plant life which comprises contacting said plant life with an herbicidal amount of S (0,0 dimethylphosphorothio) N (phenyl) o methoxybenzenethioimide.

9. A method of controlling plant life which comprises contacting said plant life with an herbicidal amount of v )T F R S S'TC ORB wherein R is selected from the class consisting of substi- 0 tuted and unsubstituted lower allgyl, phenyl, carbalkoxylk l an th r up Q the srm wherein R and R are lower alkyl; and R and R are selected from the class consisting of substituted and unsubstituted lower alkyl and substituted and unsubstituted phenyl, the substituents for the lower alkyl radicals of R, R and R being selected from the group consisting of chloroand bromoand those for the phenyl radicals of R and R being selected from the group consisting of haloand alkoxy-.

12. A method of controlling plant life which comprises contacting said plant life with an herbicidal amount of S (carbethoxymethylthio) Q (methyl) N (phenyl)- thiocarbamidate.

13. A method of controlling plant life which comprises contacting said plant life with an herbicidal amount of S- (phenylthio -O- (ethyl -N- (phenyl thiocarbimidate.

14. A method of controlling plant life which comprises contacting said plant life with an herbicidal amount of O- (isopropyl) -N- (phenyl thiocarbimidate.

15. A method of controlling plant life which comprises contacting said plant life with an herbicidal amount of S (0,0 dirnethylphosphorothio) O (isopropyl) N- 10 (phenyDthiocarbimidate.

References Qited in the file of this patent UNITED STATES PATENTS 2,891,059 Malz et al June 16, 1959 2,965,535 Birum Dec. 20, 1960 3,018,215 Pianka Jan. 23, 1962 3,044,981 Malz et al. July 17, 1962 3,053,876 Malz et a1. Sept. 11, 1962 3,070,493 Price et a1 Dec. 25, 1962 

6. A METHOD OF CONTROLLING PLANT LIFE WHICH COMPRISES CONTACTING SAID PLANT LIFE WITH AN HERBICIDAL AMOUNT OF AT LEAST ONE COMPOUND OF THE FORMULA 